NPH Insulin

NPH insulin (or neutral protamine Hagedorn) (also known as Humulin N, Novolin N, Novolin NPH, NPH Iletin II, and isophane insulin), is an intermediate-acting insulin given to help control the blood sugar level of those with diabetes. NPH was created in 1936 when Nordisk formulated "isophane" porcine insulin by adding neutral protamine to regular insulin.

This is a suspension of crystalline zinc insulin combined with the positively charged polypeptide, protamine. When injected subcutaneously, it has an intermediate duration of action, meaning longer than that of regular insulin, and shorter than ultralente, glargine or detemir.